The invention relates to a backshell for a connector, the backshell consisting of a cylindrical metallic part in which a cable comprising screening braid is inserted and which comprises means for establishing electrical contact between the screening braid and the backshell.
A backshell of this kind has to meet several requirements: Reliable electrical contact must be established with the screening braid of the cable in order to guarantee the electromagnetic compatibility required by various standards. It should also be as easy as possible to manufacture and assemble and provide strain relief for the cable.
In a known backshell of the above type (cf. Techn. Information TL-EMV of the firm PFLITSCH GmbH & Co. KG, p. 20) contacting is effected by pressing the screening braid between the inclined faces of two cones. In this case a spring which presses the two cones towards one another must be provided inside the backshell, and there is a risk of individual detached stranded wire pieces or free stranded wire ends coming into contact with the earthed, or grounded parts of the backshell.
In another known backshell of the type initially mentioned (Techn. Information . . . , as above, p. 7) contact is effected via a helical continuous spring which is inserted between two metallic contact elements where the spring, is disposed in the circumferential direction and presses onto the screening braid of the cable when compressed inwards. This seal also requires a relatively high number of parts; a further disadvantage is that contact is jeopardised by the setting behaviour of the spring with increasing aging.
In addition, as already mentioned, the cable must be provided with a strain relief in backshells of this kind.
This means that a pull acting on the cable should not be transmitted to the electrical contacts and take effect at the latter, but must instead be absorbed beforehand through a connection between the cable sheath and the backshell. Because of the mechanical structure, together with the measures for creating suitable electrical contact, the safeguards against pull are often inadequate in the known backshells.
The object of the invention is to provide an improved backshell of the type initially mentioned.